Trisaccharides isomers, galactinol and osmotic imbalance associated with CO2 stress in strawberries

Treatment with high CO2 atmospheres is effective in preventing strawberry decay and increasing firmness. Nevertheless, CO2 stress generates energy disturbances associated with a high rate of fermentation. This study was designed to measure the impact of high CO2 stress (3 d, 40 kPa CO2) and its subsequent removal on fruit quality, osmotic balance and water relations. Fructo-trisaccharides isomers and raffinose were characterized and quantified by mass spectrometry (MS and MS2). CO2 stress removal was marked by both a rapid upsurge in the ratio of unfreezable water to total water and an osmotic adjustment prompted by the accumulation of soluble sugars, 1-kestose, raffinose and galactinol. Due to strong increase in galactinol concentrations, we propose it as a suitable biomarker for fruit having undergone stresses associated with osmotic imbalance.